Bring 4 cups of low-sodium chicken broth to a boil and whisk in 1 cup of stone-ground grits. Return to a boil, cover, and cook over low heat for 20-30 minutes, stirring often, until the liquid is absorbed.
Meanwhile, cook 9 chopped bacon slices in a large skillet over medium heat until crisp. Lift out, leaving the fat in the pan.
Sear 545g of large peeled and deveined shrimp in the bacon fat for 1-2 minutes per side, until pink. Transfer to a plate.
Melt half of the 6 tablespoons of butter in the skillet. Cook ¼ cup of chopped onion, ½ chopped green bell pepper, and 3 minced garlic cloves until soft. Whisk in 3 tablespoons of all-purpose flour.
Whisk in 1½ cups of low-sodium chicken broth, 1 teaspoon of seafood seasoning, 1 teaspoon of Cajun seasoning, and ¼ teaspoon of cayenne pepper. Simmer until thickened, then stir in the shrimp and bacon off the heat.
Stir the remaining butter and 1 cup of shredded cheddar into the grits. Season the grits and sauce with salt, then top the grits with the shrimp, 3 chopped scallions, ⅓ cup of chopped parsley, and the juice of ½ lemon.
